Preparation of copper thin films at ambient temperature by microwave plasma-enhanced chemical vapor deposition from the copper (II) acetylacetonate-argon-hydrogen system

Copper-containing films were prepared at room temperature by microwave plasma-enhanced chemical vapor deposition from the Cu(C5H7O2)2-Ar-H2 system. The structure and composition of films as well as the concentration depth profiles of Cu, Si, C, and O atoms in the Cu/Si and Cu/Cr/Si contact structures were determined by x-ray-diffraction techniques, Auger electron spectroscopy, Rutherford backscattering spectroscopy, and nuclear reaction analyses. Carbon atoms were found as major impurities in the deposited material. The carbon content and resistivity of films were strongly dependent on the direct bias voltage of substrates and gas-phase composition. Pure copper films with a resistivity of 2–3 μΩ cm were deposited on Si substrates with a direct bias voltage of −50 V and a hydrogen-rich Cu(C5H7O2)2-Ar-H2 gas phase.